Vertical-axis rotary loop-taker for sewing machines



t J. G. BATTING 2,370,930

VERTICAL-AXIS ROTARY LOOP-TAKERS FOR SEWING MACHINES Filed March 6, 1942 2 Sheets-Sheet Gamma;

March 6, 1945. J. G. G. BATTING VERTICAL-AXIS ROTARY LOOP-TAKERS FOR SEWING MACHINES John GQ'Bmsan Mme:

Patented Mar. 6, 1945 UNITED STATES PATENT OFFICE VERTICAL-AXIS ROTARY'LOOP-TAKER FOR-SEWING MACHINES John G. :G. .Batting westport, Conm, assignor to The Singer Manufacturing Company, fElizabeth, N. 3., a corporation of New Jersey :AppllcationMarc'h 6, 1942, Serial No; 5433.600

6 Claims.

This invention relates to lubricating means'for sewing machine loop-takers, and more particularly to loop-takers of the vertical-axis rotary hook type in which a thread-carrier is journaled in a raceway of and is restrained against rotation with the loop-taker.

The primary objector the invention is to provide a sewing machine with simple means designed to insure adequate lubrication of the the thread-carrier raceway of a vertical-axis'rotary loop-taker during the operation of the sewing machine and to obviate excess lubrication of said raceway when the sewing machine is out of operation and when the machine is thereafter brought into operation. 1

Other and more specific objects of the invention will be apparent from the following description and claims.

The invention consists'in the combination of lubricant pumping and feeding means for supplying lubricant to the raceway of a vertical-axis rotary loop-taker, as hereinafter described inconnection with the accompanying drawings, in which:

Fig. 1 is an enlarged vertical section, partly in front side elevation, .of the stitch-forming mechanism of a sewing'machine containing one 'em bodiment of the present improvement, the section being taken lengthwise of the machine in a plane containing the axis ofrotaticn of the rotary looptaker. Fig. 2 represents :2. fragmentary vertical section similar to Fig. 1 and illustrates a modified form of lubricant-pumping means. Fig. 3 represents a horizontal section of the modified lubricaht-pump'on substantially-the 'line"3 -3 *of Fig. 2; Fig. 4 also represents a fragmentary vertical machine has the usual work-supporting vbed plate Ill provided'with slide-plates l I and 12 hisposed at opposite sides of a'throat p1a'te 13 having freed-slots H. Operating "through'the feedslo'ts H of the throat-plate is 9. feed-dog pro- 'vided with apertures 16 to receive the vertically and laterally actuatedneedles I of a compound or combined needle and feed-dog work-advancing mechanism which may be of any 1151131 01 suitable construction. "Ihe-feed-clog I 5i opposed by a spring-depressed presser-ioot 8 having clearance-slots ltztor the needles-l1. Whilethe-pres- 'ent improvement is iii-part illustrated as embod- .a vertically disposed loop-taker shaft 21 which is ied in a sewing machine having two work-feeding needles, it is to be understood that the invention tion of lock stitches :is a rotary loop-taker v211.

'I'he loop-taker 20 isof the'rotary'hook type having its axis of rotation substantially parallel to the needle lfl'and substantially :normal to the plane of the wcrk-support l u, 1H and L2. The Y loop-taker 20 has the'usual upwardly open cupshaped body ofwhich the cylindrical side wall is provided "with a needle-thread loop-seizing beak 2| and, internally, with a horizontally disposed raceway J22- i Journaled in the raceway :22 of the I loop-taker 20, as illustrated 'in Fig. 1 of the drawings, is a peripheral bearing-rib iii of a thread-carrier 24. The thread-carrier is restrained against rotation with theloop-takerimand to this end the threadcarrier is :providedwitha nose '25 inengagement with a stop-Jug '26 depending 'tirom the throat- .plate 13. r

The loop-taker 20 iszcarriedby the upper enducf preferably .integral with the bottom wall 28. of the loop-takerbodyv At its upper end-directly below the bottom wall 428 of the loop-taker body, the

loop-taker shaft 2] isenlar'ged'or other-Wise provided with an vactuatingeccentric 29. The eccentric 29 is embraced by the suitably apertured end .of a-short pitman 30., of which the opposite end is connected.in-any usual :orsuitable manner with conventional; means ;(;not shown), for slightly oscillating the thread-carrier 24 in adirection opposite .to :the direction of rotation ofv thelooptaker 20.

, The loop-taker shaft 21 isrotatablyjournaled .in the usual supporting :bracket 3| suitably securedzupon a bushing :32 carried by a lug 33 'depending :trom the wbed-plate l 0,; said bushing .being apertured to provide a bearing for ahorizontally disposedrotary actuating or bed-shaft extending lengthwise of the bed-plate Ill.

The loop-taker supporting bracket .31 is formed with verticaily'spaced upperand lower bearinglugs 35 and 36 which are respectively provided with apertures .31 and 381 in vertical alinement. Disposed in the aperture :31: of the-upper bearinglug :35 :is a.:ball-.bearing:39-1'in'which the looptaker shaft 2'! is rotatably .journaled. A washer 40 is preferably.interposedtbetween the ball-bearing 39 andtheeccentriclfl of-the-loopstaker shaft 21 to'minimize iri'ction; said washerpreferably having its lower face circumferentially recessed to receive a ring 4| of felt or similar lubricantconducting material. Threaded into the upper bearing lug aperture 31 from the under side thereof is a nut 42 which locates the ball-bearing 39 in said lug-aperture 31.

' The loop-taker shaft 21 is similarly journaled in the lower bearing-lug 36 of the loop-taker bracket 3!. To this end, the lower bearing-lug aperture 38 is provided with a ball-bearing 43 which is vertically located in set position by a nut 44 suitably apertured to provide clearance for the shaft 2'1 and threaded into the bearinglug 36 from the under side thereof. A washer 45 overlies the lower ball-bearing 43 and is circumferentially recessed in its lower face to re ceive a ring d6 of felt or similar lubricant-conducting material. suitably secured to the bracket-lugs in the desired set positions of the loop-taker shaft ballbearings; Secured to the loop-taker shaft 21, by a setscrew 47, is the hub ofa driven spiral-gear 48 suitably rotated from. the bed-shaft 34 so that the loop-taker 28 rotates twice for each complete endwise reciprocation of the needle IT. The hub of the spiral-gear 48 is disposed between the nut 42 ofthe upper bearing-lug and the washer t5, overlying the lower ball-bearing. The looptaker shaft 2'! is therefore restrained against endwise movement in the supporting bracket 31.

The'bottom wall 25 of the loop-taker 28 is axially provided in its upper face with an annular recess 49, and said recess 49 is counterbored to receive a'rclosure-disk i! which i preferably substantially flush with the inner or upper face of said bottom wall 2-8. The bottom wall ,28 of the loop-taker is also provided with a duct 5| extending radially outwardly from the recess 49 and suitably plugged at its oute end. The ra-.

dial duct 5| is opento thelower end of a generally vertical duct 52 provided in the cylindrical side wall of the loop-taker 28. The upper end of the side wall duct 52 is open to the loop-taker raceway :22 and the lower end of said duct 52 issuitably sealed orplugged below the radial duct 5|. The connectedrducts 151 and 52 together form a lubricant-conduit connecting the looptaker recess 49 with the raceway 22.

The loop-taker shaft 21 has a longitudinal axial bore 53 extending throughout the length of the shaft, whereby said bore 53 is open 'at the lower end of the shaft and is open at its upper .end to the loop-taker recess 49 which, preferably, is diametrically larger than the shaft-bore. 53.

portion of thenut 44 therefore comprises, in effeet, a nipple of the lubricant reservoir 56.

The threaded portion 54 of theshaft 2'! extends downwardly into the pump-cavity 58 of the lubricant-reservoir and the thread 54 is directionally spiralled to function during the operation of the machine to pump lubricant downwardly'toward the lower end of'the shaft. vThe lubricant is thereby forcedupwardly through the open bore 53 of the shaft 21 and is supplied to a lubricant-feeding wick 59 disposed in the upper portion of the shaft-bore 53 for rotation with the shaft; the lower end of said wick preferably being disposed a substantial distance above the level of the supply of lubricant in the reservoir 56, and the upper end of the Wick 59 extending into the loop-taker recess d9. Inasmuch as the wick 59 rotates with the shaft 2d, the

lubricant is thrown off from the upper end of the wick, during the operation of the machine, into the annular recess 49 of the loop-taker. The lubricant is thereby supplied to the loop-taker ducts' 5l and 52 connected to said recess, and

jwhich ducts deliver the lubricant to the threadcarrier'raceway 22 of the loop-taker.

The nuts .42 and 44 may be 7 of the Wick 59.

- While the lubricant is therefore pumped from the reservoir 56, the'wick 59 comprises lubricant-feeding means which controls the delivery of the pumped lubricant to the raceway of the loop-taken, The cylindrical wall of the pumpcavity 58 is spaced from the shaft-thread 54 suitably to obtain the desired pumping effect. Preferably, the pumping force is such as ,merely to insure that the lubricant reaches the lower end However, under certain conditions it may be preferred topump the lubricant with sufficient force to supplement the capillary lubricant-feeding action of the wick 59, in which event the-pump-activity is proportioned accordingly.

.As the pumping of the lubricant ceases upon stopping of the machine, no lubricant is supplied to the wick 59 when the machine is idle. This arrangement obviates any possibility of the wick becoming so saturated with lubricant, while the machine is idle, as to deliver an excess of lubricant when the machine is again started in operation.

bore being connected, as before, with the threadcarrier raceway of the loop-taker.

The loop-taker shaft 63 has a diametrically reduced lower end portionv 63', extending downwardly through the reservoir 56 and into the pump-cavity 6|; said ,shaft being peripherally: provided, within said cavity, with lubricant-impelling. teeth 66,.thereby to form a centrifugal pump. The teeth 66 are shaped to agitate the lubricant within the pump-cavity in directions substantially tangential to the shaft 63 upon rotation of saidshaft, thereby to induce circular movementv of the lubricant under pressure into the constricted recess 62 of the, pump-cavity 61. As upward movement of the lubricant, which is under pressure in the pump-cavity recess 62, is

opposed by the lubricant-supply in the reservoir,

the lubricant is forced downwardly through a duct 61 provided in the bottom wall of the pumpcavity 6| and disposed in' vertical alinement with the recess 62. v I

The duct Bl opens into a conicallyconstricted valve-portion 68 of' a horizontally extending transverse duct 69leading to the open lower end of a vertically disposed tube 101 fixed inan aperdantidischargedfrom the upper endoi the tube. 8311s freeto drain. downwardly inithei shaft-bore ture "in the "bottom wan or; the pump-cavity 8|; said tube "extending eupwardly' into the shaft bore' 84 into proximity-wither lower end of' the wick'65. The tuber-10,. of; which; the upper end .disposedra substantial distance :above' the lubricant-reservoir; is'preferably spaced from the in the tube 10 equal in height to the lubricantsupply in the reservoir. In the operation of the machine, the'shaft 63: is rotated "at high speed, whereby the described" centrifugal pump forces the lubricant upwardly in the tube 10 and supplies lubricant to the wick 65. Excess lubricant not absorbed by the wick 65 drains through the bore 64 of the loop-taker shaft 63. When the machine is out of operation, no lubricant is supplied to the wick 65, whereby excess saturation of the wick is obviated at the beginning of the operation of the machine.

In the further modified form of the improvement, illustrated in Figs. 4 and 5 of the drawings, the bottom wall 12 of the lubricant-reservoir 13 is provided in the underside thereof with an annular recess forming a vertical cylindrical pump-cavity M. Abottom closure-plate 15 for the pump-cavity is attached, as by screws 16, to the under side of the bottom-wall 12 and sealed by a suitable gasket 11. The top wall 18 of the pump-cavity 14, which wall is also the bottom wall of the reservoir 13, is provided with an opening 19 connecting the lubricant-reservoir 13 with the pump-cavity.

The vertically disposed loop-taker shaft 80 extends downwardly through the reservoir 13 and through the connection-opening 19 into the pump-cavity 14; said shaft having a longitudinal bore 8| provided in the upper portion thereof with a lubricant-feeding wick 82 connected with the thread-carrier raceway of the loop-taker, as illustrated in Fig. 1. Extending upwardly into the bore 8| of the loop-taker shaft and preferably into proximity to the lower end of the wick 82 is a stationary tube 83 spaced from the loop-taker shaft 80; the tube 83 being fixed in an aperture of the bottom closure-plate l5.

Carried by the lower end of the loop-taker shaft 80, within the pump-cavity I4, is a centrifugal lubricant-impeller having a, plurality of substantially radial vanes extending into close proximity to the cylindrical side wall of the pump-cavity. Opening into the pump-cavity ll, radially thereof, is a horizontal duct 86 connected by conical valve-opening 81 with a Vertical duct 88 Connected with the duct 88 is one end of an angular duct 89 provided in the closure-plate 15; the opposite end of said duct 89 being open to the lower end of the stationary tube 83. A valve-screw 90 is threaded into the wall 12 and has a conically pointed end adjustably extending into the valve-opening 81, thereby to provide for controlling the effective action of the pump In the operation of the machine, the rotating impeller 84 develops a lubricant'pressure sufficient to supply lubricant to the wick 82, the efilciency of the pump being regulatable by adjustment of the valve-screw 90. Excess lubri- 8i"; Thistmodificationlikewise has the: inherent advantage of obviatingexcess saturatiomof the 82 when the machine is-out of operation].

- Having thus set forththei nature oi the irivention what I claim herein isc -1. In a sewing machine having a horizontal-1y disposed "work support, a vertical-axis rotary shaft-disposed substantially normal to said worksupport and' having a longitudinal bore open at the lower end of said shaft, a lQop taker carried by the upper end of said shaft and having a thread-carrier raceway, lubrica-nt conductin'g connections between said bore of the rotaryshaft and said "raceway, lubricant-supply means includinga cup: having a pump-cavity, said cup having "the lwall thereof apertured to rovide: a

lubricant-discharge conduit leading from said pump-cavity and connected with said shaft-ibore endwise of said shaft, lubricant-pump means carried by the lower end of said shaft and extending into said pump-cavity, and means for controlling the delivery to said raceway of lubricant supplied to said shaft bore by said pump means.

2. In a sewing machine having a horizontally disposed work-support, a vertical-axis rotary shaft disposed substantially normal to said worksupport and having a longitudinal bore open at the lower end of said shaft, a loop-taker carried by the upper end of said shaft and having a thread carrier raceway, lubricant conducting connections between said bore of the rotary shaft and said raceway, lubricant-supply means including a cup having a pump-cavity, lubricant-pump means carried by the lower end of said shaft and extending into said pump-cavity, a lubricantpump discharge conduit leading from said pumpcavity, said conduit including atube extending upwardly from said cup into said bore of the rotary shaft in spaced .relation to said shaft, and means for controlling the delivery to said raceway of lubricant supplied to said bore of the rotary shaft by said pump means.

3. In a sewing machine, a vertical-axis rotary shaft having a longitudinal bore open at the low-.

er end of said shaft, a loop-taker carried by the upper end of said shaft and having a threadand leading from said pump-cavity, said conduit carrier raceway, lubricant-conducting connections between said bore of the rotary shaft and said raceway, lubricant-supply means including a cup having a pump-cavity, lubricant-pump means carried by the lower end of said shaft and extending into said pump-cavity, alubricant-pump I discharge conduit leading from said pump-cavity i and including a tube extending upwardly into said bore of the rotary shaft, valve-means in said discharge conduit, and a lubricant-feeding wick disposed in the upper end portion of said shaft bore above the upper end of saidtu'be.

4. In a sewing machine, a vertical-axis'rotary being connected with the bore of said shaft endwise of the shaft, and a metering screw threaded into said wall to extend into said conduit.

i I 5. Ina sewing machine having a horizontally disposed work-support, a vertical-axis rotary shaft having a longitudinal .bore open at the lower end of'said shaft, a loop-taker carried by the .,-upper end of said shaft and having a threadand said raceway,, a lubricant-supply reservoir having a pump-cavity, said shaft having the lower portion thereof extendingthrough said reservoir and into said pump-cavity, centrifugal pump means carried by said shaft within said pumpcavity, a lubricant-pump discharge conduit leading from said pump-cavity and connected with said shaft bore endwise of said shaft, and a lubricant-feeding wick disposed in. said shaft bore entirely above the level of the lubricant-supply in said reservoir.

' 6. In a sewing machine, a vertical-axis rotary carrier raceway, lubricant-conducting connections between said bore of the rotary shaft and said raceway, a lubricant-supply reservoir provided at the under side thereof with a pump-cavity, said pump-cavity having a removable bottom closure-plate and said shaft having the lower portion thereof extending through said reservoir and into'said pump-cavity, a tube extending upwardly from said closure-plate into the bore of said shaft, centrifugal pump means carriedby said shaft within said pump-cavity, a lubricantpump discharge conduit leading from said pumpcavity and connected with said tube, valve means in said discharge conduit, and a lubricant-feed ing wick disposed in the upper end portion of the upper end of said tube. 

